Bug 1919237

Created attachment 1749743 [details]
poc

To Reproduce

```shell
vim -u NONE -X -Z -e -s -S poc -c :qa!
```

Debug Info

```shell
/src/vim# ASAN_OPTIONS=alloc_dealloc_mismatch=0:allocator_may_return_null=1:allocator_release_to_os_interval_ms=500:check_malloc_usable_size=0:detect_container_overflow=1:detect_odr_violation=0:detect_leaks=1:detect_stack_use_after_return=1:fast_unwind_on_fatal=0:handle_abort=1:handle_segv=1:handle_sigill=1:max_uar_stack_size_log=16:print_scariness=1:quarantine_size_mb=10:strict_memcmp=1:strict_string_check=1:strip_path_prefix=/workspace/:symbolize=1:use_sigaltstack=1 src/vim_asan -u NONE -X -Z -e -s -S /mnt/disk/out/vim/vim-fuzzer-out/SFeBCp/crashes/id:000036,sig:11,src:044477,op:havoc,rep:8 -c :qa!
=================================================================
==25097==ERROR: AddressSanitizer: heap-use-after-free on address 0x62500000f108 at pc 0x0000007fecea bp 0x7fffffffd650 sp 0x7fffffffd648
READ of size 8 at 0x62500000f108 thread T0
SCARINESS: 51 (8-byte-read-heap-use-after-free)
    #0 0x7fece9 in find_pattern_in_path /src/vim/src/search.c:3867:13
    #1 0x5e7609 in ex_findpat /src/vim/src/ex_docmd.c:8379:2
    #2 0x5e99ab in ex_psearch /src/vim/src/ex_docmd.c:8323:5
    #3 0x5d277b in do_one_cmd /src/vim/src/ex_docmd.c:2588:2
    #4 0x5cc8b8 in do_cmdline /src/vim/src/ex_docmd.c:1003:17
    #5 0x7ec3ee in do_source /src/vim/src/scriptfile.c:1401:5
    #6 0x7eb03d in cmd_source /src/vim/src/scriptfile.c:971:14
    #7 0x7eaf1e in ex_source /src/vim/src/scriptfile.c:997:2
    #8 0x5d277b in do_one_cmd /src/vim/src/ex_docmd.c:2588:2
    #9 0x5cc8b8 in do_cmdline /src/vim/src/ex_docmd.c:1003:17
    #10 0x5cf181 in do_cmdline_cmd /src/vim/src/ex_docmd.c:592:12
    #11 0x9c0df7 in exe_commands /src/vim/src/main.c:3056:2
    #12 0x9bfc44 in vim_main2 /src/vim/src/main.c:760:2
    #13 0x9bd071 in main /src/vim/src/main.c:412:12
    #14 0x7ffff6cba83f in __libc_start_main /build/glibc-e6zv40/glibc-2.23/csu/../csu/libc-start.c:291
    #15 0x41d768 in _start (/src/vim/src/vim_asan+0x41d768)

0x62500000f108 is located 8 bytes inside of 8736-byte region [0x62500000f100,0x625000011320)
freed by thread T0 here:
    #0 0x49733d in free (/src/vim/src/vim_asan+0x49733d)
    #1 0x6cfd9b in vim_free /src/vim/src/misc2.c:1807:2
    #2 0x4d1815 in apply_autocmds_group /src/vim/src/autocmd.c:2172:6
    #3 0x4d363d in apply_autocmds /src/vim/src/autocmd.c:1621:12
    #4 0x9522e8 in win_enter_ext /src/vim/src/window.c:4716:2
    #5 0x94da28 in win_split_ins /src/vim/src/window.c:1329:5
    #6 0x949216 in win_split /src/vim/src/window.c:817:12
    #7 0x5c6835 in prepare_tagpreview /src/vim/src/ex_cmds.c:5082:10
    #8 0x7fe008 in find_pattern_in_path /src/vim/src/search.c:3852:4
    #9 0x5e7609 in ex_findpat /src/vim/src/ex_docmd.c:8379:2
    #10 0x5e99ab in ex_psearch /src/vim/src/ex_docmd.c:8323:5
    #11 0x5d277b in do_one_cmd /src/vim/src/ex_docmd.c:2588:2
    #12 0x5cc8b8 in do_cmdline /src/vim/src/ex_docmd.c:1003:17
    #13 0x7ec3ee in do_source /src/vim/src/scriptfile.c:1401:5
    #14 0x7eb03d in cmd_source /src/vim/src/scriptfile.c:971:14
    #15 0x7eaf1e in ex_source /src/vim/src/scriptfile.c:997:2
    #16 0x5d277b in do_one_cmd /src/vim/src/ex_docmd.c:2588:2
    #17 0x5cc8b8 in do_cmdline /src/vim/src/ex_docmd.c:1003:17
    #18 0x5cf181 in do_cmdline_cmd /src/vim/src/ex_docmd.c:592:12
    #19 0x9c0df7 in exe_commands /src/vim/src/main.c:3056:2
    #20 0x9bfc44 in vim_main2 /src/vim/src/main.c:760:2
    #21 0x9bd071 in main /src/vim/src/main.c:412:12
    #22 0x7ffff6cba83f in __libc_start_main /build/glibc-e6zv40/glibc-2.23/csu/../csu/libc-start.c:291

previously allocated by thread T0 here:
    #0 0x4975bd in malloc (/src/vim/src/vim_asan+0x4975bd)
    #1 0x6ce307 in lalloc /src/vim/src/misc2.c:925:11
    #2 0x6ce423 in alloc_clear /src/vim/src/misc2.c:852:9
    #3 0x94efa9 in win_alloc /src/vim/src/window.c:4892:14
    #4 0x94cdac in win_split_ins /src/vim/src/window.c
    #5 0x949216 in win_split /src/vim/src/window.c:817:12
    #6 0x4c9ebe in do_argfile /src/vim/src/arglist.c:662:10
    #7 0x4c9c1d in ex_next /src/vim/src/arglist.c:727:2
    #8 0x5d277b in do_one_cmd /src/vim/src/ex_docmd.c:2588:2
    #9 0x5cc8b8 in do_cmdline /src/vim/src/ex_docmd.c:1003:17
    #10 0x7ec3ee in do_source /src/vim/src/scriptfile.c:1401:5
    #11 0x7eb03d in cmd_source /src/vim/src/scriptfile.c:971:14
    #12 0x7eaf1e in ex_source /src/vim/src/scriptfile.c:997:2
    #13 0x5d277b in do_one_cmd /src/vim/src/ex_docmd.c:2588:2
    #14 0x5cc8b8 in do_cmdline /src/vim/src/ex_docmd.c:1003:17
    #15 0x5cf181 in do_cmdline_cmd /src/vim/src/ex_docmd.c:592:12
    #16 0x9c0df7 in exe_commands /src/vim/src/main.c:3056:2
    #17 0x9bfc44 in vim_main2 /src/vim/src/main.c:760:2
    #18 0x9bd071 in main /src/vim/src/main.c:412:12
    #19 0x7ffff6cba83f in __libc_start_main /build/glibc-e6zv40/glibc-2.23/csu/../csu/libc-start.c:291

SUMMARY: AddressSanitizer: heap-use-after-free /src/vim/src/search.c:3867:13 in find_pattern_in_path
Shadow bytes around the buggy address:
  0x0c4a7fff9dd0: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
  0x0c4a7fff9de0: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
  0x0c4a7fff9df0: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
  0x0c4a7fff9e00: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
  0x0c4a7fff9e10: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
=>0x0c4a7fff9e20: fd[fd]fd fd fd fd fd fd fd fd fd fd fd fd fd fd
  0x0c4a7fff9e30: fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd
  0x0c4a7fff9e40: fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd
  0x0c4a7fff9e50: fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd
  0x0c4a7fff9e60: fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd
  0x0c4a7fff9e70: fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd
Shadow byte legend (one shadow byte represents 8 application bytes):
  Addressable:           00
  Partially addressable: 01 02 03 04 05 06 07
  Heap left redzone:       fa
  Freed heap region:       fd
  Stack left redzone:      f1
  Stack mid redzone:       f2
  Stack right redzone:     f3
  Stack after return:      f5
  Stack use after scope:   f8
  Global redzone:          f9
  Global init order:       f6
  Poisoned by user:        f7
  Container overflow:      fc
  Array cookie:            ac
  Intra object redzone:    bb
  ASan internal:           fe
  Left alloca redzone:     ca
  Right alloca redzone:    cb
  Shadow gap:              cc
==25097==ABORTING
```

After releasing the global variable curwin in  prepare_tagpreview , it is referenced on line 3867.

```c
//src/search.c L3847
#if defined(FEAT_QUICKFIX)
		    // ":psearch" uses the preview window
		    if (g_do_tagpreview != 0)
		    {
			curwin_save = curwin;
			prepare_tagpreview(TRUE, TRUE, FALSE);
            ^^^^^^^^^^^^^^^^^^
		    }
#endif
		    if (action == ACTION_SPLIT)
		    {
			if (win_split(0, 0) == FAIL)
			    break;
			RESET_BINDING(curwin);
		    }
		    if (depth == -1)
		    {
			// match in current file
#if defined(FEAT_QUICKFIX)
			if (g_do_tagpreview != 0)
			{
			    if (!GETFILE_SUCCESS(getfile(
					   curwin_save->w_buffer->b_fnum, NULL,
                       ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
						     NULL, TRUE, lnum, FALSE)))
				break;	// failed to jump to file
			}
			else
```



Environment:

- version : commit e2edc2ed4a9a229870b1e1811b0ecf045b84e429
- OS: Ubuntu 16.04



Additional context

compile argument：

```shell
#!/bin/bash -eux
export CC="clang-11"
export CXX="clang-11++"
export LDFLAGS="-fsanitize=address"
export CFLAGS="-O1 -g -fsanitize=address -fno-omit-frame-pointer"
export CXXFLAGS="-O1 -g -fsanitize=address -fno-omit-frame-pointer"
cd /src/vim/ && ./configure --with-features=huge --enable-gui=none && make
```



Credit: 1vanChen of NSFOCUS Security Team